package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

//公共controller
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    /**
     * 文件上传
     * @date 2023/2/6 17:50
     * @param file
     * @return R<String>
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //转存图片
        String filename = file.getOriginalFilename();
        //图片的后缀
        String suffix = filename.substring(filename.lastIndexOf("."));
        //使用UUID生成文件名，防止上传的文件名重复
        String newFileName = UUID.randomUUID().toString() + suffix;
        //判断转存的目录是否存在
        File dir = new File(basePath);
        if(!dir.exists()){
            dir.mkdirs();
        }
        //转存
        try {
            file.transferTo(new File(basePath + newFileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(newFileName);
    }

    /**
     * 文件下载
     * @date 2023/2/6 18:30
     * @param name
     * @param response
     * @return R<String>
     */
    @GetMapping("/download")
    public R<String> download(String name, HttpServletResponse response){
        try {
            //输入流，通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));
            //输出流，通过输出流将文件写回浏览器，在浏览器中显示该图片
            ServletOutputStream outputStream = response.getOutputStream();
            //响应的是图片文件
            response.setContentType("img/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while((len = fileInputStream.read(bytes)) != -1){
                outputStream.write(bytes, 0 ,len);
                outputStream.flush();
            }

            fileInputStream.close();
            outputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return R.success("");
    }
}
